In order to realize a new type of secondary battery for use in an electrically-powered car, it is necessary to develop battery material that is capable of achieving dramatically high-energy density and high capacity, enabling low cost, and assuring high safety, and to develop a manufacturing technique for such batteries.
An electrically-powered car (fuel-cell powered car) is a car that is driven by electric energy generated by a fuel cell. Although a fuel cell has sufficiently higher efficiency than that of a gasoline engine, it has a characteristic that the maximum effect is achieved particularly in a low-load region. Therefore, it is imperative that a high-performance secondary battery is used to supply electric power and supplement the driving energy for the driving during high-load power output such as acceleration in order to further improve the efficiency of the electric car system.
Furthermore, the utilization of a regenerating brake capable of recovering energy during deceleration, instead of relying on a mechanical brake, leads to higher efficiency in energy use. By recovering energy from regenerating braking, the secondary battery is temporality charged, and the charged electricity can be used for the driving energy as the need arises. The utilization of the secondary battery that can instantaneously supply electric power during driving, and instantaneously recover and store energy during braking depending on the driving states is indispensable for higher efficiency in energy use. Theoretically, the only battery that can satisfy these requirements for a car-mounted secondary battery is a lithium battery, and the practical usability of a (large-scale) car-mounted lithium battery is the key technology to establish a fuel-cell car system capable of making the maximum use of the high efficiency of the fuel cell.
Such lithium battery is, in general, produced by applying active material containing lithium and active material containing carbon to aluminum foil and copper foil respectively, drying them, and repeating these steps to form them on both sides (front surfaces and back surfaces) of the foils. In this process, a coating apparatus (coating machine) is used to apply the active material to the metal thin films.    Patent Citation 1: Japanese Unexamined Patent Application Publication No. 2001-321710.